Air ionization is an effective method of creating or eliminating static charges on non-conductive materials and isolated conductors. Air ionizers generate large quantities of positive and negative ions in the surrounding atmosphere which serve as mobile carriers of charge in the air. As ions flow through the air, they are attracted to oppositely charged particles and surfaces. Creation or neutralization of electrostatically charged surfaces can be rapidly achieved through this process.
Air ionization may be performed using electrical ionizers which generate ions in a process known as corona discharge. Electrical ionizers generate air ions through this process by intensifying an electric field around a sharp point until it overcomes the dielectric strength of the surrounding air. Negative corona occurs when electrons are flowing from the electrode into the surrounding air. Positive corona occurs as a result of the flow of electrons from the air molecules into the electrode.
Ionizer devices, such as an electrostatic charging system, an ionization system, or an alternating current (AC) or direct current (DC) charge neutralizing system, take many forms such as ionizing bars, air ionization blowers, air ionization nozzles, and the like, and are utilized to create or neutralize static electrical charge by emitting positive and negative ions into the workspace or onto the surface of an area. Ionizing bars are typically used in continuous web operations such as paper printing, polymeric sheet material, or plastic bag fabrication. Air ionization blower and nozzles are typically used in workspaces for assembling electronics equipment such as hard disk drives, integrated circuits, and the like, that are sensitive to electrostatic discharge (ESD). Electrostatic charging systems are typically used for pinning together paper products such as magazines or loose leaf paper.
Ionizers typically include at least one ionization emitter that is powered by a high voltage supply. The charge produced by the ionization emitter is proportional to the current flowing from the high voltage supply into the ionization emitter. Over time, an ionizer may accumulate debris. In order to maintain optimal the performance of the ionizer, it is necessary to clean the ionizer in order to remove the debris. As an ionizer accumulates debris, the ionizer's charge will decrease and, therefore, the current flowing from the voltage supply into the ionizer will also decrease. Conventionally, the current flowing from the voltage supply into the ionizer can be measured by using the return leg of the high voltage transformer or supply, but this allows only the sum current from the supply to be measured. It is difficult to monitor the current directly flowing into the ionization emitter because conventional current monitoring devices and circuits do not provide voltage isolation from the high voltage supply. Monitoring current is particularly difficult when multiple ionizers are connected in parallel to a single high voltage supply.